Nuclear poly(A)-binding protein 1 is an ATM target and essential for DNA double-strand break repair. Issue 2 (14th December 2017)

• Record Type: Journal Article
• Authors: Gavish-Izakson, Michal; Velpula, Bhagya Bhavana; Elkon, Ran; Prados-Carvajal, Rosario; Barnabas, Georgina D; Ugalde, Alejandro Pineiro; Agami, Reuven; Geiger, Tamar; Huertas, Pablo; Ziv, Yael; Shiloh, Yosef
• Is Part Of: Nucleic acids research. Volume 46:Issue 2(2018)
• Page Start: 730
• Page End: 747
• Publication Date: 2017-12-14
• Subjects: Nucleic acids -- Periodicals; Molecular biology -- Periodicals; 572.805
• DOI: 10.1093/nar/gkx1240
• Languages: English
• ISSNs: 0305-1048

Abstract

Abstract: The DNA damage response (DDR) is an extensive signaling network that is robustly mobilized by DNA double-strand breaks (DSBs). The primary transducer of the DSB response is the protein kinase, ataxia-telangiectasia, mutated (ATM). Here, we establish nuclear poly(A)-binding protein 1 (PABPN1) as a novel target of ATM and a crucial player in the DSB response. PABPN1 usually functions in regulation of RNA processing and stability. We establish that PABPN1 is recruited to the DDR as a critical regulator of DSB repair. A portion of PABPN1 relocalizes to DSB sites and is phosphorylated on Ser95 in an ATM-dependent manner. PABPN1 depletion sensitizes cells to DSB-inducing agents and prolongs the DSB-induced G2/M cell-cycle arrest, and DSB repair is hampered by PABPN1 depletion or elimination of its phosphorylation site. PABPN1 is required for optimal DSB repair via both nonhomologous end-joining (NHEJ) and homologous recombination repair (HRR), and specifically is essential for efficient DNA-end resection, an initial, key step in HRR. Using mass spectrometry analysis, we capture DNA damage-induced interactions of phospho-PABPN1, including well-established DDR players as well as other RNA metabolizing proteins. Our results uncover a novel ATM-dependent axis in the rapidly growing interface between RNA metabolism and the DDR.